Feed mechanism for sewing machines



Ocf. 5, 1926.

1,602,142 s. w. AVIS FEED MECHANISM FOR SEWING MACHINES Filed Jan. 19 1924 :s Sheets-Sheet 1 Oct. 5 1926.

s. w. AVIS FEED MECHANISM FOR SEWING MACHINES F11 Jan. 19, 1924 3 Sheets-Sheet 2 s. w. AVIS FEED MECHANISM FOR SEWING MACHINES Oct. 5 1926. Q

Filed Jan. 19 3 Sheets-Sheet 5 'rable and shows a plan or a Patented Get. 5, 1926.

SAMUEL VI. AVIS, OF WEST HARTFORD. CONNECTICUT.

FEED-MECHANISM FOR snwrne vmcnnvnsn Application filed January 19, 1924. Serial No. 687,351 I This invention relates to the mechanisms provided for feedlng the material to be.

,stitched through sewing machines-particularly machines which are designed'to be run at high speeds, and it is illustrated as adapted to an overedge machine of the type illustrated and described in my application for Patent '#393,223 filed July 1 1920.

In machines of this character it is desir-' able not only to be able to change thelength of movement of the feed dogs in order [to increaseor decrease the number of stitches per inch'in the material ted,'and on account of the naturerof the work to be ableto have the respective teed tances, but also to be able to vary .thetravel of the fed dogs with relation to each'oth er'" while the machine is running.

The Ob186t of the tomanutacture and assemble, is dueiiticient in operation and is capable of a delicate yet wide range of adjustment without stopping the machine. I

cheap In the accompanying drawings Fig.1 lilZlClllIlQOf the type re fer-red to with the worlr plate broken away to expose the feed mechanism; F g. 2 1s a vertical longitudinal section of themachine with the improved teed. Fig. 3 is a trans-1 verse section taken on the dotted line 3 3 an elevation of onesidej near one end. Fig. 5 is an elevation of the T m on Fig. 1. Fig. 4 1s other side showing the meansprovided ,tor.

the differential 6 is a view looking up the effecting the variation of feed. Fig. parts shown in Fig. 5. of one'ot the feed dog carriers and the adjustable mechanism for reciprocating it. Fig. 8 is a section of the adjustable "teed dog reciprocating mechanism on the'line 8-8 on Fig. 7. Fig. 9 is a vertical transverse section taken on the plane indicated by the In the machine illustratedlas described in the application referred to, all of the active mechanisms are operated from a single cam dogs travel different dis- 1 invention 1S to produce a variable differential feed for machines of the class mentioned, which 1s comparatlvely.

Fig. 7 is a side view Fig. 13, is a per- 7 shattl which supportedfbelow the work plate 2 by. the bed block 3 in the casing 4, with its aitis parallel to the line of feed of P thework to be stitched. Onth'e cam shaft is, a cam. 5 that through thefintermediate.

mechanism causes the reciprocation'otthej feed {dogs 6 and 7 in adirectioniparallel with the camshaft, .and onthe shaft is a cam '8 that through the intermediate fmechanism' causes theoscillation of the feed dogs,

the feed dogs being advanced with their teeth above 'the top oftheneedle plate 9 and then at the limitof the. advance movement oscillated so as to carry the teeth below the 'needle' plate, then retracted with theteeth in this lower plane, and finally at'the'end'of their return movement oscillated so aslto 2' lift the teeth abovethe-plane of the needle vplate,'as fullyset-forth in the prior .application mentioned.

The front teed'dog Gisdetachably 'fa stened ,to a carrier slide 10', and the rear feed dog 7 is detachably fastened. to a carrier slide 11. Theiteed 'dogsmayhave teeth of any conventional shape and arrangement.

The feed dog carriers are fitted together so. that they. may be reciprocatecl independentlylot each other but will fill an opening in an oscillatory cradle 12, in which they are gamm so that they will oscillate together as onepl ece on a longitudinal axis when the cradle 1s rocked. The carriers are shown as 1triangular in crossisection but they maybe made in other forms which will slidably-fit the opening through the cradle. and yet bev oscillated'loy the rocking-ofthe cradle. AL

cover plate 13 extending cross the top of the opening in the cradle retains the carriers in place. The under surface of the cradle is cylindrical. and is fitted-to a correspond- I ingly shaped cavity in the top ofablock 14. In the top groove 15 that is concentric with the under side of the cradle. Attached to the. under side of the needle plate 9 is a strip 16 that fits the curved groovein the cover of the.

cradle so as to hold the cradle in place. This strip forms the airisupon which thecradle is rocked. Nhen'the needle plate is removed the cradle withLthe carriers and feed dogs is free to be lifted from the casing. When the cover plate is untastened from the cradle the carriers and feed dogs can be taken out. i The cradle is held from longitudinal movement but is freeto be oscillated on a longitudinal axis, and the feed dog-carriers of the cover plate is a curved may be reciprocated and the rear feed dog carrier atits front end has a fork 19 projecting'outwardly toward the other side, by

means of which it may be reciprocated. The

fork 17 on the under side of the cradle contame a shoe 20 on the swinging end of a yoke-shaped lever 21 that is mounted on a pivot stud 22 that is eccentrically mounted.

in the front side of the bed block 3. The

cam 8 on the cam shaft 1 lies in the opening in the yoke 21 so that the rotation of the shaft through this cam will at the correct times oscillate the lever and rock the cradle which carries the feed dogs.

The fork 1.8 at the front end of the front feed dog carrier is occupied by a shoe 24: on the upper end of an angle lever 25, and the fork l9at the front end of the rear fe'ed'dog .carrier is occupied by a shoe 26 on the upper end of a similar angle lever 27. The oscillations of these levers cause the reciprocation of the feed dog carriers. In order that these levers may be oscillated independently of each other the lever 27 has a tubular arbor 28 and the lever a solid arbor 29 that 'is fitted within the tubular arbor so that these arbors will be concentric and'yet one may turn relatively to the other. The arbors are rotatably mounted 1n an opening 111 a block 80 that is fastened to the front .end

of the block 3. The lower end of the lever 25 has a roll 31 lying in a cam slot 32 in a bell crank plate 33. that has a long tapering arbor 34. The lower end of the lever 27 has a roll 35 lying in a similar slot 36 in a hell crank plate 37 that has a long tapering arbor 38. In radial slots 89 in each of the hell crank plates is a shoe 4 0 mounted on a stud 41 projecting from tl e side ofa vertically movable yoke-shaped slide 42. .The cam 5 on the main shaft lies in the opening in this slide so that the rotation of the shaft through the cam at. the correct periods moves the slide up and down and through the bell crank plates oscillates the levers that reciprocate the feed dog carriers.

The arbor 88 is eccentrically mounted in a cylinder i3 that is rotatably adjustable in a hub a l extending inward from one side of the casing, while the arbor 34 is eccentrically mounted in a cylinder 45 that is rotatablyadjustable in a hub 46 extending in ward from the other side of the casing. 13y rotatably adjusting these cylinders the angular relations of the axes of the bell crank plates to the axes of the shoes onthe yoke whichengage and oscillate the crank plates which is graduated.

as the yoke moves up and down, may be changed. In other words turning the eylinc ers the radial slots 39 in the bell crank plates may be adjusted more or less angularly toward an d from the up and down path of movement of the shoes 40 that are carried by the yoke slide and which lie in the radial slots and oscillate the bell crank plates. By this means the throw of the bell crank plates may be independently varied so asto give the angle levers greater or less oscillating movements and the feed dog carriers more or less travel.

in order to adjust the throw of the rear feed dog carrier the cylinder i3 has a stem 47 that proj c s out-ward through a plate 48 fastened to the side of the casing. On this stem is a disk ii) the periphery of which is graduated. When the nut 50 on the stem 47 is loosened the disk 479' may be grasped and turned and the cylinder rotated so as to carry the axis of the bell crank plate 3'? to such position that the throw of the plate.

will cause the desired movement to be imparted to the rear feed doe. l hen the adjustment has been effected to give they required travel to the rear feet l doe; the nut 50 is tightened so as to clamp the parts in the positions to which they are adjusted.

In order to effect a variation of the travel of the feed dog's while the machine is in operation the cylinder lf) which carries the arbor 3 ithe bel. crank plate'33 may be provided with a gear 51 and mesliing with this gear may be a pinion on a shaft 53 which projects through a plate astened to the side of the casing. in the outer end of the shaft is a disk the periphery of Upon tun. 1 this disk the shaft is turned and through the gears the cylinder 4-5 cal ying the arbor 3i i rotated. @n the shaft outside of an arm s the disk is A spring 57 coiled around the hub of the arm has one endengaged with a stud 58 projecting from the plate and the other end engaged with a stud 59 projecting; from the inside of the arm. The arm is clamped to the disk by a nut 60. i hen the arm ,is turned the disk will he turned so that through the gears the parts will be adjuster to give the front feed do the desired travel. The arm may be moved by hand or by any other desired means for effecting}; the adji :tment. A stop pin 61 is arranged to project from the plate in position to stop the arn when it is turned back by the spring. Surrounding the shaft between the plate ant the disk is an annula: plate which has a stop hip; 63 and that is clamped inposition b a screw 64. This plate is adjusted so the stop lug will be engaged and will stop the cam in the required locality to give the desired tance of travel to the front feed dog. i 1 the arm is released the S'QlliiQ returns it to the normal position. "Upon loosening the dog.

2A; feed mechanism for se\ chines, comprising a reciprocatory front-- ifeed dog carrier, a reciprocatory rear feed dog carrier, an oscillatorycradle supporting o carrier,- .a

nut 60 the handlemaybe freed from the disk so that the disk may beiadjusted to give the normal amount offeed to the front feed dog dogs may be varied; and any adjustment 0 1"- the relationsof the travel of onedogto the. other may beeflected without stopping the 111%16111116. 1 1 i The invention claimed' is: f I i 1. A feed mechanism for sewing machines, comprising ,aplurality of reciprocatory feed, dogcarrie'rs, an oscillatory cradle supportsaid carriers, mechanism for reciprocating carriers independently of said ing said cradle, and mechanism for oscillating said. I cradle with the reciprocatory feed dog carriers inounte'd thereon; transversely of the line offeed whereby the feed dogs carried thereby will travel forward 1n an upper path and will travel backward in a path;

lower and at one side of the path of forward travel. j

mg masaid carriers, mechanism for oscillating said cradle transversely of the line offeed whereby the feed dogs carried thereby will travel forward-in an upper path and will travel backward in a path lower and at one side of the path offorward travel, and mechanism for reciprocating the feed dog carriers in dependently of said cradle.

3. A feed mechanism for sewing machines,

com risin a1 reci rocator front feed do arrier, a 'recipro'catory rear feed dog carrier, an oscillatory cradle supporting said carriers, mechanism, foroscillating said L F F 1 cradletransversely o; the line of iced wiiereby the feed dog's carried thereby will travel forward in an upper path and will travel" 1 backward in a path lower and at one side of .tl1e path of forward travel, and mechanism for reciprocating the-feed dog carriers independently of each other and independently 4;. Afeed mechanism for sewing machines, comprising a'reciprocatory front feed dog reciprocatory rear feed dog carrier, an oscillatory cradle in which said carriers are sli'dably fitted, mechanism forv oscillating said cradle transversely of the line of feed whereby the feed dogs carried tiei'eby 'w ll'travel forward in an upper other l rough said cradle. I A feed, mechanism for sewingniachines, :compr sing a reciprocatory front feed dog carrier, a reciprocatory rear feed dog carr er ,"an oscillatory cradle supporting :SllCl carriers, mechanism for oscillat ng said.)

cradle transversely of the line of feed where by the'feed dogs carried thereby; will travel forwardinan npper path-and will travel backward in aipatli lower and at one side of the'patli of forward travel, mechanismfori reciprocating; thefront feed dog carrier,

path and will: travel backward in a path" lowerandat one side of the path of forward travel, and meclianism for reciprocating the feed. dog carriers independently of .each 7 r1 1 DH.

mechanism for-reciprocating the rear feed I dog-carrier,-.and means for adjusting said 6. feed n echanisnifor sewin machines i comprising a reciprocatory front feed dog c'atory rear feed dog carsupporting said ea V V 'ory cradle 1638,: mechanism for ,OSClllQ-tlHg said vers'ely o t the line offeed whereupper path and will travel.

of the path, of forward travel, mechanism for reciprocating the/feed dog -carriers,' and means forvarying theiactions of said-reciprocating mechanisms independently of each other; 1 I

7. A feed mechanism for sewing machines, comprising aplurality of reciprocatory feeddog carriers, an oscillatory cradlein whicl reciprocating mechanism wlierebythej travel 7 ofuthe' feed dog carriers may be varied. v a

by the feed dogs carried thereby will travel forward in an oackward in a path lower'and' at OIIG'SlClQ said carriers are slidably fitted, mechanism for reciprocating said carriers independently of said cradle, and mechanism for oscillating said cradle with the .reciprocatory feed dog carriers'fitted therein,transversely of the line of feed whereby the feed dogs can 1 riedthereby w ll travel forward. in aniipper' path and will travel backward in a path lower, and at one side of tliepath of for ward travel. I I

8. A feed mechanism for sewing machines,

con iprising a plurality of reciprocatory feed dog carr1er's,an osclllatorycradle support ing said carriers,'mechanism for reciprocato ing "said. carriers independently of said cradle, mechanisms for varying the action of said reciprocating mechanism on the respective feed dog carriers,-and mechanism a, "for oscillating saidcradle with the feed dog carriers mounted thereon, transversely of the line of feedwhere'by thefeed dogs carried thereby will travel'forward in an upper path and will travel backward in a path lower andatone side ofthe path of forwarditr-avel. p r a 9. A feed mechanism for sewing machines, comprising two reciprocatory feed dog carriers, an oscillatory cradle supporting said carriers, independently adjustable mechanisms for reciprocating said carriers independently of-each other and of said cradle, and mechanism for oscillating said cradle with the reciprocatory feed dog carriers mounted thereon, transversely of the line of feed whereby the feed dogs carried there by will travel forward in an upper path and will travel backward in a path lower and at one side of the path of forward travel.

10. A feed mechanism for sewing ma chines, comprising two reciprocatory feed dog carriers, an oscillatory cradle in which said carriers are slidably fitted, adjustable mechanism for reciprocating said carriers independently of each other and of said cradle, and mechanism for oscillating said cradle transversely of the line of feed whereby the feed dogs carried thereby will travel forward in an upper path and will travel backward in a path lower and at one side Of the path of forward travel."

11. A feed mechanism for sewing machines, comprisingtwo reciprocatory feed dog carriers, said-carriers being fitted together and slidable with relation to each other, an oscillatory cradle supporting said carr ers, mechanism for reciprocating said carriers independently of said cradle and independently of each other, and mechanism for oscillating said cradle with said feed dog carriers mounted thereon, transversely of the line of feed whereby the feed dogs carried thereby will travel forward in an upper path and will travel backward in a path lower and at one side of the path of forward travel.

12. A feed mechanism for sewing machines, comprising two feed dog carriers, said carriers being fitted together and slidable with relation to each other, an oscillatory cradle with a groove containing said cairiers, removable cover retaining the carriersin said groove, mechanism for oscillating said cradle transversely of the line of feed whereby the feed dogs carried thereby will travel forward in an upper path and will travel backward in a path lower and at one side of the path of forward travel, and mechanism for reciprocating the feed dog carriers independently of each 'other and said cradle.

A3. A feed mechanism for sewing machines, comprising two feed dog carriers slidable with relation to each other, oscillatory means supporting said carriers, mechanism for oscillating said supporting means, mechanisms for reciprocating the feed dog carriers independently of each other and independently of said supporting means, and adjustable means for varying the action of one of the feed dog reciprocating mechanisms, said adjust-able means including gears and means for rotating said gears.

14. A feed mechanism for sewing machines, comprising two feed dog carriers slidable with relation to ea-ch other, an oscillatory cradle supporting said carriers, mechanism for oscillating said cradle transversely ofthe line of feed whereby the feed dogs carried thereby will travel forward in an upper path and will travel backward in path lower and at one side of the path of forward travel, mechanism for reciprocating the feed dog carriers independently of each other, adjustable means for varying the action of both of said reciprocating mechanisms, one of said means including an operating arm by which the adjustment may be obtained while the machine is running.

15. A. feed mechan-isn'i for sewing machines, comprising two feed dog carriers slidable with relation to each other, an oscillatory means supporting said carriers,

mechanism for oscillating said, supporting justable means including a spring controlled operating arm, and stops for limiting the movements of said arm, whereby the action of one of said reciprocating mechanisms may be varied from normal and then returned to normal.

16. A. feed mechanism for sewing ma chines, comprising a reciprocatOry front feed dog carrier, a reciprocatory rear feed dog carrier, and a sidewise oscillatory cradle in which said carriers are slidably supported and by which they are oscillated sidewise at the ends of their reciproca-tory movements about an axis parallel to the direction of feed, said supporting means and the carriers being assembled in and removable from the machine asa'unit.

17. A feed mechanism unit for sewing machines, con'mrisingtwo independent reciprocato ry feed dog carriers, and a cradle supporting said carriers, said cradle mounted to oscillate transversely of the line of feed of the feed dog carriers and said carriers being fitted together and slidably fitting an opening in said cradle.

18. A feed mechanism for sewing machines, comprising two feed dog carriers slidable with relation to each other, an oscillatory means supporting said carriers, mechsaid reciprocatory mechanisms may be varied from a desired normal and returned to normal.

19. In combination ith the needle plate of a sewing machine, of a feed mechanism comprising a reciprocatory front feed dog carrier, a reciprocatory rear feed dog carrier, an oscillatory cradle supporting said carriers, the axis of oscillation of said cradle and extending parallel With the line offeed,

feed dogs attached to the carriers at one. side of. said axis of oscillation of the cradle j i and means for reciprocating the feed dog carriers and oscillating the cradle.

SAMUEL W; AVIS.

being at the under side of the needleplate 1Q. 

